Professor of Physiological Sciences
College of Veterinary Medicine
Donald Bolser’s primary research focus is analyzing cough and its role in health and disease.
Bolser’s research program has evolved from a focus on the pharmacology of cough to the investigation of fundamental mechanisms of brainstem circuits responsible for the production and coordination of airway protective behaviors (cough and swallow) in mammals. The long-term goal of his research is to define brainstem mechanisms that control and coordinate cough and swallow.
The operational features, identity, and specific neural mechanisms which regulate and coordinate the occurrence of cough and swallow to optimize airway protection are unknown. Bolser has identified novel functional brainstem systems that regulate the expression of cough and recently discovered control mechanisms responsible for coordinating cough and swallow to reduce the risk of aspiration.
His central hypothesis is that a “core” cough/respiratory network is reconfigured by neuronal assemblies, dynamically organized into regulatory elements that control airway defensive behaviors. He has termed these cooperative populations of neurons behavioral control assemblies (BCAs). Similar to command neurons studied in other systems, BCAs are postulated to weigh “risk/benefit” data to make decisions to produce a variety of appropriate behaviors. Using systemic and neuropharmacological methods, he has established the presence of brainstem BCAs that provide both excitatory and inhibitory control of airway protective behaviors.
Bolser has also employed aspiration-promoting protocols to discover novel coordinating strategies used by the brainstem control system to minimize the occurrence of aspiration. These segregation strategies include: time-dependent suppression or facilitation of swallowing, selective enhancement of cough and swallow following an aspiration event, spatial increases in upper esophageal sphincter motor drive, and evidence for tracheal sensory afferent control of the expression of swallowing. Collectively, these strategies represent the influence of a complex airway protective control system that was heretofore unrecognized.